I’ve ran my pc on 100% cpu and gpu for months straight before. It’s ok maybe even better than hot cold hot cold cycles all the time as long as temp is within the correct range. Since chips have no moving parts they only way they can fail is by heat cycling so one could argue keeping them at hot operating temp all the time is preferable to running them to a lower temp then allowing them to cool over and over.
I will say I ran my i7 2600k at a 4.4ghz overclock for 5years straight pc on 24/7/365 , after 5 years started getting occasional crashes, turned down OC to 4.2 , no more crashes. So there is some heat degradation somewhere how it works I don’t know